Many different types of devices are known for cutting body hair. Hair may be cut using scissors, but to minimize the hair length, other types of devices are used, such as shaving devices and trimmers. In the early days, men used razor blades to shave their beards. Later on electric shaving became popular, also for women. Today, electric hair cutting devices vary from trimmers for trimming facial hair to electric razors for shaving a beard or other body parts.
The usual goal when shaving is to achieve the closest shave possible while minimizing skin irritation. Most facial hair shaving is done by males, but woman may also shave their body or facial hair.
A traditional shave consists of using a razor blade to cut the facial hair. Several techniques have been developed over centuries in this field, making it possible to achieve a close shave without irritation. The main principle is to cut the hair without cutting the skin. This may require several stages in the shaving process. First, the skin hair is conditioned to initiate the shaving process. The goal is to optimize the hair and skin characteristics to achieve an optimal shave. The conditioning may consist of moistening and/or heating the skin/hair. Next, the hair is iteratively cut until a safe against the grain shave can be achieved. This may consist of first cutting the hair in its growth direction, i.e. cutting only the hair without touching the skin. A second stage of shaving is cutting the hair perpendicularly to its growth direction, preparing the hair for the last cutting stage. Finally, in the last stage, the remainder of the hair is cut against its growth direction. At all of these stages, the moistening of the skin is maintained and the blade is kept at a minimal distance from the skin, thus minimizing skin injury.
During the post-shaving routines, the user should close the pores left open after the shaving and minimize any infection possibility from the shaving operation. This is achieved by lowering the face temperature, thereby causing the pores to naturally close and through the application of (chemical) disinfectants, destroying any infection causes which could have resulted from the shaving procedure.
Although the described shaving procedure is very effective to achieve irritation-free close shaving, the procedure is generally regarded as time consuming and difficult, as it requires unique knowledge of the hair growth in each part of the face and a precise application of the shaving sequence. Facial hair grows according to different patterns for different people. While some people present a very uniform top-down hair growth pattern over their face, most people present several variations in this pattern. Differences in patterns can consist of hair growing in different local directions relative to the skin, creating swirls, branches or sinks where the hair converges.
Several interactive hair cutting systems are known to help a user during the cutting of the hair. Publication WO2013/096572 describes a system providing guidance to a user. Information indicative of the position of a hair cutting device relative to the part of the body is generated and used to guide the user. A camera on an electronic computing device may collect images of the user and assess their present hair length and style and determine what styles and lengths are possible with the user's hair. However, the system described in WO2013/096572 cannot determine the hair growth direction for optimizing the shaving result.
So there is a need for a system that provides guidance to a user as to the optimal shaving sequence during the shaving procedure.